Ask Lemmygrad

While I cannot exactly answer everything about communist society, I will say that this question from your friend (seemingly not Marxist, I might add) is a bit strange: Do they think people just do not do things unless they have a wage or profit incentive?

I would imagine (again, I have not studied this part of communism) that under communism, there would be people who would want to do some of the things you mentioned because there would actually be a sense of community under communism (no class divisions means that there will be no exploiter-exploited relationship to divide people), and people would not need an "incentive" (if we mean incentive in the context of money being given so that people can do things) to provide services or do anything productive (hell, the wage incentive existing does not prevent people from helping others out despite it not being related to their wages).

In fact, profit gets in the way of incentives for doing productive things because it is only productive insofar as it relates to profit. If there is no profit, nothing productive in a given field is likely to be done. Eliminating classes would eliminate the fetters of capitalism on people in doing the things that they want to do, but they would also be able to better help out their community.

I think of it like this: Under capitalism, class divisions created in society not only cause them to experience capitalism differently, but feel the effect of things (like trash buildup) differently due to their different economic statuses causing some to experience the same situation differently or different experiences to exist entirely. The out-of-touch capitalists know little and care little about trash buildup in an impoverished neighborhood if they do not have to go there and if it does not serve as an anti-profit obstacle, so they would have no reason to pay others to clean it up (even if they pay others to clean up trash, others are cleaning up the trash, not them, so they will not understand the severity of the problem). On the other hand, if no class distinctions existed, people would have different roles but would experience similar environments (if they live in the same approximate area), and if something negatively affected a community, then there would be no "shield" from it in the form of capitalist privileges and no distancing from the problem because a negative thing affecting a community would affect all members of a classless society in a roughly equal manner (of course, I only mean roughly, because other factors would certainly affect the relative desire of any given person to provide a service to the community, but it will be less of a factor than it would under capitalism).

Sorry for the answer not explaining all aspects of the question, but your friend does not seem to understand that people do not stop doing things because of no classes existing.

Edit: I wrote this using my last remaining brain fumes before going to sleep, so some stuff might be inaccurate but I just really wanted to answer the question because it involves annoying arguments some libservatives make (yes I combined those two), yet are hardly difficult to counter if you understand basic human empathy.